METHOD AND APPARATUS FOR DETERMINATION OF FIBER ORIENTATION IN PAPER OR PAPERBOARD WEB

摘要

The present invention relates to a method and apparatus for determination oforientation of fibers (1) in a material (3) such as a paper or paperboard webcomprised of elongated fibers (1) of high moisture content. In the method, thematerial (3) is subjected to an alternating electric field (E) of the RF ormicrowave frequency range lying in the plane of the material and the changecaused by the presence of said material (3) in said alternating electric field(E) is measured. According to the invention, the direction of said alternatingelectric field (E) is altered during the measurement, whereby the material (3)need not be rotated with respect to the resonator for the measurement.